AVIS-IBIS

Birds of Indian Subcontinent

Daily energy expenditure of singing great reed warblers Acrocephalus arundinaceus

Publication Type:Journal Article
Year of Publication:2008
Authors:Hasselquist, D, Bensch, S
Journal:Journal of Avian Biology
Volume:39
Issue:4
Date Published:2008
ISBN Number:1600-048X
Keywords:Acrocephalidae, Acrocephalus, Acrocephalus arundinaceus, Acrocephalus orientalis, Acrocephalus scirpaceus
Abstract:According to honest signalling theory, signals must be costly to produce to retain information about the signaller's quality. The song produced by male birds during breeding is a vocal “ornament” used for intra- and inter-sexual purposes. The energetic cost of this vocal signal remains a contentious issue. We used the doubly labelled water method to measure field metabolic rate by estimating CO2 production and then convert this to daily energy expenditure (DEE) in great reed warbler males singing under natural conditions (10 at low to moderate intensity and 7 at very high intensity from dawn to dusk). There was a significant positive relationship between singing intensity and DEE. From this relationship we extrapolated the average DEE for intensely singing males (i.e., males producing song sounds 50% of the time and hence sitting at their elevated song post in the top of a reed stem more or less continuously throughout the ∼20 h of daylight) to 3.3×BMR (basal metabolic rate) and for non-singing males to 2.2×BMR. The mean DEE measured for the seven males singing with very high intensity was 3.1×BMR. The maximum measured DEE for a single male was 3.9×BMR, i.e. close to the maximum sustainable DEE (4×BMR), and the minimum DEE was 2.1×BMR for a male singing at very low intensity. These results imply that producing intensive advertising song in birds may incur a substantial cost in terms of increased energy expenditure.
URL:http://dx.doi.org/10.1111/j.0908-8857.2008.04427.x
Short Title:Journal of Avian Biology
Taxonomic name: 
Acrocephalidae (Birds), Acrocephalus (Birds), Acrocephalus arundinaceus (Birds), Acrocephalus orientalis (Birds), Acrocephalus scirpaceus (Birds)
Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith